ASHLAND - As of last week, residents are not allowed to water their lawns or wash their cars because of restrictions imposed by the Department of Public Works. According to the state Department of Environmental Protection, Ashland did not know where 28 percent of its water was going in 2012.

On Monday, town officials argued that those two events are unrelated.

“I wouldn’t make a correlation between (water restrictions) and unaccounted for water,” said Town Manager Anthony Schiavi.

Restrictions on water use are determined by levels at Hopkinton Reservoir, Ashland’s primary source of water. However, missing water is largely attributed to a metering problem caused by unknown pipe leaks or broken meters around town, according to DPW Director David Manugian in a phone interview.

“For us, it’s about metering. Are we accurately measuring the water we are using?” said Manugian.

Ashland saw a spike in missing water in 2012 because of a leak in Cold Spring Brook.

According to the town’s annual water report for 2013, Ashland generated 483 million gallons of water, 403 million of which was metered. Of the remaining 80 million gallons, about 33 million was classified as “confidently estimated municipal use.” That includes water that was not measured due to faulty meters, hydrant flushing and water breaks among other causes, said Manugian.

Fire hydrants do not have meters which means water used to fight fires also falls under that category. The report estimates 1.25 million gallons of water was used for fire protection and training in 2013.

The remaining 47 million gallons makes up 13 percent of Ashland’s total water supply that was unaccounted for in 2013. Manugian spoke with the DEP on Monday and predicts that number may fall closer to 10 percent - the maximum amount of water that should be unaccounted for, according to state standards.

Water restrictions are also seasonal. They are more common in the summer due to dry conditions and increased water use. Unmetered water can slip through during any time of year, said Manugian.

To minimize missing water, the town hired a private company every year to measure running water and find leaks. The town is also running a meter replacement program. Last year, the town replaced 600 meters in a condominium complex in town. There are about 6,000 water meters in Ashland, according to Manugian.

Even without concerns about missing water, Ashland has had problems maintaining reservoir water levels in the past. In November, the town had to request an emergency water connection from the Massachusetts Water Resources Authority. The Board of Selectmen will hold public hearings beginning in September to talk about installing a permanent MWRA connection.

“It behooves us to make sure we have a reliable, sustainable source of water for the community,” said Schiavi.

Anamika Roy can be reached at 508-626-3957 or aroy@wickedlocal.com. Follow her on Twitter @anamikaroy.